Exam 29: Heredity

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -The ABO blood type is a good example of a(n) inheritance.

Figure 29.1 -Given the information in Figure 29.1, what would be the genotype of the offspring designated by the blank square?

A family has four offspring belonging respectively to ABO blood groups A, B, O, and AB. Give the genotypes and phenotypes of the parents.

A patient is heterozygous for sickle- cell anemia. Explain why the patient would have few or no symptoms of sickle- cell anemia.

Normal vision is dictated by autosomal dominant genes.

Assume that the allele controlling brown eyes (B) is dominant over that controlling blue eyes (b) in human beings. (In actuality, eye color in humans is an example of polygene inheritance, which is much more complex than this.) A blue- eyed man marries a brown- eyed woman, and they have six children, all brown- eyed. What is the most likely genotype of the father? What is the most likely genotype of the mother? If a seventh child had blue eyes, what can you conclude about the parents' genotypes?

The X and Y chromosomes are considered the chromosomes.

Suppose an XcXc female marries an XcY man. (a) What is the probability of producing a color- blind son? (b) What is the probability of producing a color- blind daughter? (c) What is the probability of producing a daughter who is a carrier for the color- blind gene? (d) What is the probability of having four sons in a row?

Alleles may code for alternative expressions of a genetic trait.

The reason recessive genetic disorders are more frequent than disorders inherited as dominant is that .

Those characteristics that can be determined on superficial inspection of an individual are known as .

Figure 29.2 Use Figure 29.2 to answer the following: -Identify, by numbers, any known carriers.

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -Observable characteristics expressed by the genes for a trait are called the .

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -disease is a disorder of brain lipid metabolism and is an example of a recessive trait.

Genetic variation results from the crossing over and exchange of chromosomal parts that occur during meiosis II.

In incomplete dominance, the heterozygote has a phenotype intermediate between that of homozygous- dominant and homozygous- recessive individuals.

The term lethal dominant gene indicates that the gene causes death only when the individual is homozygous.

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -What would the parental gametes be from a cross of two second- generation, straight- shorthaired individuals?

Which of the following is true concerning environmental influence on genetic expression?

Among members of the Fuzzy Wuzzy tribe, we will consider two pairs of genes: F = fuzzy hair vs. f = straight hair, and T = long hair vs. t = short hair. A homozygous, straight- shorthaired male marries a homozygous, fuzzy- longhaired female (P1 generation). Their offspring (the F1 generation) intermarry and produce progeny (second generation) of four types: fuzzy- longhaired, fuzzy- shorthaired, straight- longhaired, and straight- shorthaired. The results follow a standard dihybrid pattern. -What possible genotype(s) could the second- generation, fuzzy- longhaired individuals possess?